This invention is generally concerned with document singulating apparatus and more particularly with singulating apparatus including opposed, oppositely moving belts for singulating successive documents fed thereto.
In U.S. Pat. No. 4,930,764 entitled FRONT END FEEDER FOR A MAIL HANDLING MACHINE, issued Jun. 5, 1990 to Holbrook et al., belt structure has been provided for separating successive sheets from the bottom of a stack and feeding the sheets downstream to a sheet singulating structure which includes opposed belts moving in opposite directions. And, in U.S. Pat. No. 4,909,499 entitled MAIL SINGULATING APPARATUS, issued Mar. 20, 1990 to O'Brien et al., which includes a more detailed discussion of the singulating structure of the type shown in the Holbrook et al. patent, a mail piece singulating structure has been provided where oppositely moving upper and lower belts have been interleaved to form a nip for separating the successive lowermost mail pieces from mail pieces stacked thereon. And, in U.S. Pat. No. 4,615,519 entitled MAIL SEPARATING DEVICE, issued Oct. 7, 1986 to Holodnak et al., a belt structure has been provided for handling vertically oriented mail pieces to assure that only one mail piece at a time is fed into a mail processing machine. The belt structure is mounted on bell crank that is resiliently urged toward an adjustable stop member so that a predetermined minimum gap is maintained between the outer surface of the belt of the belt structure and the adjacent surface of a feeding roller regardless of the extent of wear on the belt.
Thus, it is generally known in the art to provide belt structures for separating successive documents from the bottom of the stack and forming a nip of interleaved belts for separating successive lower most documents from others stacked thereon. It is also generally known in the art to provide a document singulating apparatus for singulating documents fed thereto which are uprightly oriented on an edge thereof and have oppositely facing upright surface.
In U.S. Pat. No. 5,074,540 entitled DOCUMENT SINGULATING APPARATUS, issued Dec. 24, 1991 to Belec et al., belt structure has been provided for separating and singulating successive sheets vertically oriented. The belt structure includes opposed belts in an interleaved relationship moving in opposite directions with four adjustable springs used to control the forces applied to the documents being singulated. Although the Belec et al. structure has performed adequately, the trial and error adjustments to the tension of each spring effects the interrelationship of the forces of each belt. Since there are four springs involved with the adjustment, the adjustment may be difficult
Accordingly, an object of the present invention is to provide an improved apparatus for singulating documents, including for example, mail pieces that are varying in surface finish and thickness;
Another object of the present invention is to provide an improved apparatus for singulating documents fed thereto, wherein the respective documents are uprightly oriented on an edge thereof and have oppositely facing upright surfaces
These and other objects and advantages of the present invention will become apparent from an understanding of the following detailed description of the presently preferred embodiment of the present invention when considered in consideration with the accompanying drawings.